C++ RenderBlock类代码示例

String HitTestResult::innerTextIfTruncated(TextDirection& dir) const
{
    for (Node* truncatedNode = m_innerNode.get(); truncatedNode; truncatedNode = truncatedNode->parentNode()) {
        if (!truncatedNode->isElementNode())
            continue;

        if (RenderObject* renderer = truncatedNode->renderer()) {
            if (renderer->isRenderBlock()) {
                RenderBlock* block = toRenderBlock(renderer);
                if (block->style()->textOverflow()) {
                    for (RootInlineBox* line = block->firstRootBox(); line; line = line->nextRootBox()) {
                        if (line->hasEllipsisBox()) {
                            dir = block->style()->direction();
                            return toElement(truncatedNode)->innerText();
                        }
                    }
                }
                break;
            }
        }
    }

    dir = LTR;
    return String();
}

void findGoodTouchTargets(const IntRect& touchBox, LocalFrame* mainFrame, Vector<IntRect>& goodTargets, WillBeHeapVector<RawPtrWillBeMember<Node> >& highlightNodes)
{
    goodTargets.clear();

    int touchPointPadding = ceil(std::max(touchBox.width(), touchBox.height()) * 0.5);

    IntPoint touchPoint = touchBox.center();
    IntPoint contentsPoint = mainFrame->view()->windowToContents(touchPoint);

    HitTestResult result = mainFrame->eventHandler().hitTestResultAtPoint(contentsPoint, HitTestRequest::ReadOnly | HitTestRequest::Active | HitTestRequest::ConfusingAndOftenMisusedDisallowShadowContent, IntSize(touchPointPadding, touchPointPadding));
    const WillBeHeapListHashSet<RefPtrWillBeMember<Node> >& hitResults = result.rectBasedTestResult();

    // Blacklist nodes that are container of disambiguated nodes.
    // It is not uncommon to have a clickable <div> that contains other clickable objects.
    // This heuristic avoids excessive disambiguation in that case.
    WillBeHeapHashSet<RawPtrWillBeMember<Node> > blackList;
    for (WillBeHeapListHashSet<RefPtrWillBeMember<Node> >::const_iterator it = hitResults.begin(); it != hitResults.end(); ++it) {
        // Ignore any Nodes that can't be clicked on.
        RenderObject* renderer = it->get()->renderer();
        if (!renderer || !it->get()->willRespondToMouseClickEvents())
            continue;

        // Blacklist all of the Node's containers.
        for (RenderBlock* container = renderer->containingBlock(); container; container = container->containingBlock()) {
            Node* containerNode = container->node();
            if (!containerNode)
                continue;
            if (!blackList.add(containerNode).isNewEntry)
                break;
        }
    }

    WillBeHeapHashMap<RawPtrWillBeMember<Node>, TouchTargetData> touchTargets;
    float bestScore = 0;
    for (WillBeHeapListHashSet<RefPtrWillBeMember<Node> >::const_iterator it = hitResults.begin(); it != hitResults.end(); ++it) {
        for (Node* node = it->get(); node; node = node->parentNode()) {
            if (blackList.contains(node))
                continue;
            if (node->isDocumentNode() || isHTMLHtmlElement(*node) || isHTMLBodyElement(*node))
                break;
            if (node->willRespondToMouseClickEvents()) {
                TouchTargetData& targetData = touchTargets.add(node, TouchTargetData()).storedValue->value;
                targetData.windowBoundingBox = boundingBoxForEventNodes(node);
                targetData.score = scoreTouchTarget(touchPoint, touchPointPadding, targetData.windowBoundingBox);
                bestScore = std::max(bestScore, targetData.score);
                break;
            }
        }
    }

    for (WillBeHeapHashMap<RawPtrWillBeMember<Node>, TouchTargetData>::iterator it = touchTargets.begin(); it != touchTargets.end(); ++it) {
        // Currently the scoring function uses the overlap area with the fat point as the score.
        // We ignore the candidates that has less than 1/2 overlap (we consider not really ambiguous enough) than the best candidate to avoid excessive popups.
        if (it->value.score < bestScore * 0.5)
            continue;
        goodTargets.append(it->value.windowBoundingBox);
        highlightNodes.append(it->key);
    }
}

int InlineTextBox::textPos() const
{
    if (xPos() == 0)
        return 0;
        
    RenderBlock *blockElement = object()->containingBlock();
    return direction() == RTL ? xPos() - blockElement->borderRight() - blockElement->paddingRight()
                      : xPos() - blockElement->borderLeft() - blockElement->paddingLeft();
}

RenderObject *ElementImpl::createRenderer(RenderArena *arena, RenderStyle *style)
{
    if (getDocument()->documentElement() == this && style->display() == NONE) {
        // Ignore display: none on root elements.  Force a display of block in that case.
        RenderBlock* result = new (arena) RenderBlock(this);
        if (result) result->setStyle(style);
        return result;
    }
    return RenderObject::createObject(this, style);
}

FloatPoint InlineBox::locationIncludingFlipping()
{
    if (!renderer()->style()->isFlippedBlocksWritingMode())
        return FloatPoint(x(), y());
    RenderBlock* block = root()->block();
    if (block->style()->isHorizontalWritingMode())
        return FloatPoint(x(), block->height() - height() - y());
    else
        return FloatPoint(block->width() - width() - x(), y());
}

void RenderMathMLSubSup::addChild(RenderObject* child, RenderObject* beforeChild)
{
    // Note: The RenderMathMLBlock only allows element children to be added.
    Element* childElement = toElement(child->node());

    if (childElement && !childElement->previousElementSibling()) {
        // Position 1 is always the base of the msub/msup/msubsup.
        RenderMathMLBlock* wrapper = new (renderArena()) RenderMathMLBlock(node());
        RefPtr<RenderStyle> wrapperStyle = RenderStyle::create();
        wrapperStyle->inheritFrom(style());
        wrapperStyle->setDisplay(INLINE_BLOCK);
        wrapperStyle->setVerticalAlign(BASELINE);
        wrapper->setStyle(wrapperStyle.release());
        RenderMathMLBlock::addChild(wrapper, firstChild());
        wrapper->addChild(child);
            
        // Make sure we have a script block for rendering.
        if (m_kind == SubSup && !m_scripts) {
            m_scripts = new (renderArena()) RenderMathMLBlock(node());
            RefPtr<RenderStyle> scriptsStyle = RenderStyle::create();
            scriptsStyle->inheritFrom(style());
            scriptsStyle->setDisplay(INLINE_BLOCK);
            scriptsStyle->setVerticalAlign(TOP);
            scriptsStyle->setMarginLeft(Length(gSubsupScriptMargin, Fixed));
            scriptsStyle->setTextAlign(LEFT);
            // Set this wrapper's font-size for its line-height & baseline position.
            scriptsStyle->setBlendedFontSize(static_cast<int>(0.75 * style()->fontSize()));
            m_scripts->setStyle(scriptsStyle.release());
            RenderMathMLBlock::addChild(m_scripts, beforeChild);
        }
    } else {
        if (m_kind == SubSup) {
            ASSERT(childElement);
            if (!childElement)
                return;

            RenderBlock* script = new (renderArena()) RenderMathMLBlock(node());
            RefPtr<RenderStyle> scriptStyle = RenderStyle::create();
            scriptStyle->inheritFrom(m_scripts->style());
            scriptStyle->setDisplay(BLOCK);
            script->setStyle(scriptStyle.release());

            // The order is always backwards so the first script is the subscript and the superscript 
            // is last. That means the superscript is the first to render vertically.
            Element* previousSibling = childElement->previousElementSibling();
            if (previousSibling && !previousSibling->previousElementSibling()) 
                m_scripts->addChild(script);
            else                 
                m_scripts->addChild(script, m_scripts->firstChild());
            
            script->addChild(child);
        } else
            RenderMathMLBlock::addChild(child, beforeChild);
    }
}

static bool shouldScaleColumns(RenderTable* table)
{
    // A special case.  If this table is not fixed width and contained inside
    // a cell, then don't bloat the maxwidth by examining percentage growth.
    bool scale = true;
    while (table) {
        Length tw = table->style()->width();
        if ((tw.isVariable() || tw.isPercent()) && !table->isPositioned()) {
            RenderBlock* cb = table->containingBlock();
            while (cb && !cb->isCanvas() && !cb->isTableCell() &&
                cb->style()->width().isVariable() && !cb->isPositioned())
                cb = cb->containingBlock();

            table = 0;
            if (cb && cb->isTableCell() &&
                (cb->style()->width().isVariable() || cb->style()->width().isPercent())) {
                if (tw.isPercent())
                    scale = false;
                else {
                    RenderTableCell* cell = static_cast<RenderTableCell*>(cb);
                    if (cell->colSpan() > 1 || cell->table()->style()->width().isVariable())
                        scale = false;
                    else
                        table = cell->table();
                }
            }
        }
        else
            table = 0;
    }
    return scale;
}

void InlinePainter::paintOutline(const PaintInfo& paintInfo, const LayoutPoint& paintOffset)
{
    RenderStyle* styleToUse = m_renderInline.style();
    if (!styleToUse->hasOutline())
        return;

    LayoutRect bounds;
    if (RuntimeEnabledFeatures::slimmingPaintEnabled()) {
        // FIXME: Use tighter bounds.
        RenderBlock* cb = m_renderInline.containingBlock();
        bounds = cb->visualOverflowRect();
        bounds.moveBy(paintOffset);
    }
    RenderDrawingRecorder recorder(paintInfo.context, m_renderInline, paintInfo.phase, bounds);
    if (recorder.canUseCachedDrawing())
        return;

    if (styleToUse->outlineStyleIsAuto()) {
        if (RenderTheme::theme().shouldDrawDefaultFocusRing(&m_renderInline)) {
            // Only paint the focus ring by hand if the theme isn't able to draw the focus ring.
            ObjectPainter(m_renderInline).paintFocusRing(paintInfo, paintOffset, styleToUse);
        }
        return;
    }

    if (styleToUse->outlineStyle() == BNONE)
        return;

    Vector<LayoutRect> rects;

    rects.append(LayoutRect());
    for (InlineFlowBox* curr = m_renderInline.firstLineBox(); curr; curr = curr->nextLineBox()) {
        RootInlineBox& root = curr->root();
        LayoutUnit top = std::max<LayoutUnit>(root.lineTop(), curr->logicalTop());
        LayoutUnit bottom = std::min<LayoutUnit>(root.lineBottom(), curr->logicalBottom());
        rects.append(LayoutRect(curr->x(), top, curr->logicalWidth(), bottom - top));
    }
    rects.append(LayoutRect());

    Color outlineColor = m_renderInline.resolveColor(styleToUse, CSSPropertyOutlineColor);
    bool useTransparencyLayer = outlineColor.hasAlpha();

    GraphicsContext* graphicsContext = paintInfo.context;
    if (useTransparencyLayer) {
        graphicsContext->beginTransparencyLayer(static_cast<float>(outlineColor.alpha()) / 255);
        outlineColor = Color(outlineColor.red(), outlineColor.green(), outlineColor.blue());
    }

    for (unsigned i = 1; i < rects.size() - 1; i++)
        paintOutlineForLine(graphicsContext, paintOffset, rects.at(i - 1), rects.at(i), rects.at(i + 1), outlineColor);

    if (useTransparencyLayer)
        graphicsContext->endLayer();
}

VisiblePosition RenderSVGInlineText::positionForPoint(const LayoutPoint& point, const RenderRegion*)
{
    if (!firstTextBox() || !textLength())
        return createVisiblePosition(0, DOWNSTREAM);

    float baseline = m_scaledFont.fontMetrics().floatAscent();

    RenderBlock* containingBlock = this->containingBlock();
    ASSERT(containingBlock);

    // Map local point to absolute point, as the character origins stored in the text fragments use absolute coordinates.
    FloatPoint absolutePoint(point);
    absolutePoint.moveBy(containingBlock->location());

    float closestDistance = std::numeric_limits<float>::max();
    float closestDistancePosition = 0;
    const SVGTextFragment* closestDistanceFragment = nullptr;
    SVGInlineTextBox* closestDistanceBox = nullptr;

    AffineTransform fragmentTransform;
    for (InlineTextBox* box = firstTextBox(); box; box = box->nextTextBox()) {
        if (!is<SVGInlineTextBox>(*box))
            continue;

        auto& textBox = downcast<SVGInlineTextBox>(*box);
        Vector<SVGTextFragment>& fragments = textBox.textFragments();

        unsigned textFragmentsSize = fragments.size();
        for (unsigned i = 0; i < textFragmentsSize; ++i) {
            const SVGTextFragment& fragment = fragments.at(i);
            FloatRect fragmentRect(fragment.x, fragment.y - baseline, fragment.width, fragment.height);
            fragment.buildFragmentTransform(fragmentTransform);
            if (!fragmentTransform.isIdentity())
                fragmentRect = fragmentTransform.mapRect(fragmentRect);

            float distance = powf(fragmentRect.x() - absolutePoint.x(), 2) +
                             powf(fragmentRect.y() + fragmentRect.height() / 2 - absolutePoint.y(), 2);

            if (distance < closestDistance) {
                closestDistance = distance;
                closestDistanceBox = &textBox;
                closestDistanceFragment = &fragment;
                closestDistancePosition = fragmentRect.x();
            }
        }
    }

    if (!closestDistanceFragment)
        return createVisiblePosition(0, DOWNSTREAM);

    int offset = closestDistanceBox->offsetForPositionInFragment(*closestDistanceFragment, absolutePoint.x() - closestDistancePosition, true);
    return createVisiblePosition(offset + closestDistanceBox->start(), offset > 0 ? VP_UPSTREAM_IF_POSSIBLE : DOWNSTREAM);
}

LayoutUnit RenderBlockFlow::logicalRightSelectionOffset(RenderBlock* rootBlock, LayoutUnit position)
{
    LayoutUnit logicalRight = logicalRightOffsetForLine(false);
    if (logicalRight == logicalRightOffsetForContent())
        return RenderBlock::logicalRightSelectionOffset(rootBlock, position);

    RenderBlock* cb = this;
    while (cb != rootBlock) {
        logicalRight += cb->logicalLeft();
        cb = cb->containingBlock();
    }
    return logicalRight;
}

VisiblePosition RenderSVGInlineText::positionForPoint(const IntPoint& point)
{
    if (!firstTextBox() || !textLength())
        return createVisiblePosition(0, DOWNSTREAM);

    RenderStyle* style = this->style();
    ASSERT(style);
    int baseline = style->font().ascent();

    RenderBlock* containingBlock = this->containingBlock();
    ASSERT(containingBlock);

    // Map local point to absolute point, as the character origins stored in the text fragments use absolute coordinates.
    FloatPoint absolutePoint(point);
    absolutePoint.move(containingBlock->x(), containingBlock->y());

    float closestDistance = std::numeric_limits<float>::max();
    float closestDistancePosition = 0;
    const SVGTextFragment* closestDistanceFragment = 0;
    SVGInlineTextBox* closestDistanceBox = 0;

    for (InlineTextBox* box = firstTextBox(); box; box = box->nextTextBox()) {
        ASSERT(box->isSVGInlineTextBox());
        SVGInlineTextBox* textBox = static_cast<SVGInlineTextBox*>(box);
        Vector<SVGTextFragment>& fragments = textBox->textFragments();

        unsigned textFragmentsSize = fragments.size();
        for (unsigned i = 0; i < textFragmentsSize; ++i) {
            const SVGTextFragment& fragment = fragments.at(i);
            FloatRect fragmentRect(fragment.x, fragment.y - baseline, fragment.width, fragment.height);
            if (!fragment.transform.isIdentity())
                fragmentRect = fragment.transform.mapRect(fragmentRect);

            float distance = powf(fragmentRect.x() - absolutePoint.x(), 2) +
                             powf(fragmentRect.y() + fragmentRect.height() / 2 - absolutePoint.y(), 2);

            if (distance < closestDistance) {
                closestDistance = distance;
                closestDistanceBox = textBox;
                closestDistanceFragment = &fragment;
                closestDistancePosition = fragmentRect.x();
            }
        }
    }

    if (!closestDistanceFragment)
        return createVisiblePosition(0, DOWNSTREAM);

    int offset = closestDistanceBox->offsetForPositionInFragment(*closestDistanceFragment, absolutePoint.x() - closestDistancePosition, true);
    return createVisiblePosition(offset + closestDistanceBox->start(), offset > 0 ? VP_UPSTREAM_IF_POSSIBLE : DOWNSTREAM);
}

void RenderLineBreak::collectSelectionRects(Vector<SelectionRect>& rects, unsigned, unsigned)
{
    ensureLineBoxes(*this);
    InlineElementBox* box = m_inlineBoxWrapper;
    if (!box)
        return;
    const RootInlineBox& rootBox = box->root();
    LayoutRect rect = rootBox.computeCaretRect(box->logicalLeft(), 0, nullptr);
    if (rootBox.isFirstAfterPageBreak()) {
        if (box->isHorizontal())
            rect.shiftYEdgeTo(rootBox.lineTopWithLeading());
        else
            rect.shiftXEdgeTo(rootBox.lineTopWithLeading());
    }

    RenderBlock* containingBlock = this->containingBlock();
    // Map rect, extended left to leftOffset, and right to rightOffset, through transforms to get minX and maxX.
    LogicalSelectionOffsetCaches cache(*containingBlock);
    LayoutUnit leftOffset = containingBlock->logicalLeftSelectionOffset(*containingBlock, box->logicalTop(), cache);
    LayoutUnit rightOffset = containingBlock->logicalRightSelectionOffset(*containingBlock, box->logicalTop(), cache);
    LayoutRect extentsRect = rect;
    if (box->isHorizontal()) {
        extentsRect.setX(leftOffset);
        extentsRect.setWidth(rightOffset - leftOffset);
    } else {
        extentsRect.setY(leftOffset);
        extentsRect.setHeight(rightOffset - leftOffset);
    }
    extentsRect = localToAbsoluteQuad(FloatRect(extentsRect)).enclosingBoundingBox();
    if (!box->isHorizontal())
        extentsRect = extentsRect.transposedRect();
    bool isFirstOnLine = !box->previousOnLineExists();
    bool isLastOnLine = !box->nextOnLineExists();
    if (containingBlock->isRubyBase() || containingBlock->isRubyText())
        isLastOnLine = !containingBlock->containingBlock()->inlineBoxWrapper()->nextOnLineExists();

    bool isFixed = false;
    IntRect absRect = localToAbsoluteQuad(FloatRect(rect), UseTransforms, &isFixed).enclosingBoundingBox();
    bool boxIsHorizontal = !box->isSVGInlineTextBox() ? box->isHorizontal() : !style().svgStyle().isVerticalWritingMode();
    // If the containing block is an inline element, we want to check the inlineBoxWrapper orientation
    // to determine the orientation of the block. In this case we also use the inlineBoxWrapper to
    // determine if the element is the last on the line.
    if (containingBlock->inlineBoxWrapper()) {
        if (containingBlock->inlineBoxWrapper()->isHorizontal() != boxIsHorizontal) {
            boxIsHorizontal = containingBlock->inlineBoxWrapper()->isHorizontal();
            isLastOnLine = !containingBlock->inlineBoxWrapper()->nextOnLineExists();
        }
    }

    rects.append(SelectionRect(absRect, box->direction(), extentsRect.x(), extentsRect.maxX(), extentsRect.maxY(), 0, box->isLineBreak(), isFirstOnLine, isLastOnLine, false, false, boxIsHorizontal, isFixed, containingBlock->isRubyText(), view().pageNumberForBlockProgressionOffset(absRect.x())));
}

int RenderSVGContainer::calcReplacedHeight() const
{
    switch (style()->height().type()) {
    case Fixed:
        return max(0, style()->height().value());
    case Percent:
    {
        RenderBlock* cb = containingBlock();
        return style()->height().calcValue(cb->availableHeight());
    }
    default:
        return 0;
    }
}

IntRect RenderInline::clippedOverflowRectForRepaint(RenderBox* repaintContainer)
{
    // Only run-ins are allowed in here during layout.
    ASSERT(!view() || !view()->layoutStateEnabled() || isRunIn());

    if (!firstLineBox() && !continuation())
        return IntRect();

    // Find our leftmost position.
    IntRect boundingBox(linesBoundingBox());
    int left = boundingBox.x();
    int top = boundingBox.y();

    // Now invalidate a rectangle.
    int ow = style() ? style()->outlineSize() : 0;
    
    // We need to add in the relative position offsets of any inlines (including us) up to our
    // containing block.
    RenderBlock* cb = containingBlock();
    for (RenderObject* inlineFlow = this; inlineFlow && inlineFlow->isRenderInline() && inlineFlow != cb; 
         inlineFlow = inlineFlow->parent()) {
         if (inlineFlow->style()->position() == RelativePosition && inlineFlow->hasLayer())
            toRenderBox(inlineFlow)->layer()->relativePositionOffset(left, top);
    }

    IntRect r(-ow + left, -ow + top, boundingBox.width() + ow * 2, boundingBox.height() + ow * 2);
    if (cb->hasColumns())
        cb->adjustRectForColumns(r);

    if (cb->hasOverflowClip()) {
        // cb->height() is inaccurate if we're in the middle of a layout of |cb|, so use the
        // layer's size instead.  Even if the layer's size is wrong, the layer itself will repaint
        // anyway if its size does change.
        int x = r.x();
        int y = r.y();
        IntRect boxRect(0, 0, cb->layer()->width(), cb->layer()->height());
        cb->layer()->subtractScrolledContentOffset(x, y); // For overflow:auto/scroll/hidden.
        IntRect repaintRect(x, y, r.width(), r.height());
        r = intersection(repaintRect, boxRect);
    }
    ASSERT(repaintContainer != this);
    cb->computeRectForRepaint(r, repaintContainer);

    if (ow) {
        for (RenderObject* curr = firstChild(); curr; curr = curr->nextSibling()) {
            if (!curr->isText()) {
                IntRect childRect = curr->rectWithOutlineForRepaint(repaintContainer, ow);
                r.unite(childRect);
            }
        }

        if (continuation() && !continuation()->isInline()) {
            IntRect contRect = continuation()->rectWithOutlineForRepaint(repaintContainer, ow);
            r.unite(contRect);
        }
    }

    return r;
}

static inline RenderBlock* firstContainingBlockWithLogicalWidth(const RenderReplaced* replaced)
{
    // We have to lookup the containing block, which has an explicit width, which must not be equal to our direct containing block.
    // If the embedded document appears _after_ we performed the initial layout, our intrinsic size is 300x150. If our containing
    // block doesn't provide an explicit width, it's set to the 300 default, coming from the initial layout run.
    RenderBlock* containingBlock = replaced->containingBlock();
    if (!containingBlock)
        return 0;

    for (; containingBlock && !is<RenderView>(*containingBlock) && !containingBlock->isBody(); containingBlock = containingBlock->containingBlock()) {
        if (containingBlock->style().logicalWidth().isSpecified())
            return containingBlock;
    }

    return 0;
}